Problem with Texture Opacity
If it really is a transparency problem, which I'm not sure that it is, then all you have to do is uc-check the box that says Transparency under the materials tab.

However! the real problem lies within your Fresnel shading, where you have the ramp pushed aaaalll the way over to the right. you want some breathing space between the two pushey-guys or the reflective effects are super dramatic. You might also want to change Fresnel to lambert. Fresnel has effects go further without dissipation so I think that's your problem.